Artificial larynx



March 5, 1935- c. sHEARD x-:T AL

ARTIFICIAL LARYNX File'd 001;. 8, 1951 m Jv. Vm/r INVEN-roRs GAM Y ATTORNEY Patented Mar. 5, 1935 UNITED STATES PATENT OFFICE ARTIFICIAL LARYNX of Delaware Application October 8, 1931, Serial No. 567,570

1 claim.

This invention relates to an artificial larynx or voice-box adapted to replace the human larynx in its cooperation with the other organs involved in phonation.

It has for its object the reproduction by artiflcial means of the functions of the larynx with relation to making and modulating vocal sounds, and more particularly to those sounds involved in and constituting speech, whose pitch ranges between and 300 cycles per second; and averages, for the female voice about 256 cycles, and for the male voice about cycles, each second. In addition to its office as a .vocal organ, our invention has for its further object to permit inhalation and exhalation therethrough.

Further objects of our invention are hereinafter more particularly pointed out.

In the accompanying drawing forming part of this' speciiication, Figure 1 shows the voice-box and connections assembled for use; Figure 2 is a view in vertical section of Figure 1, with. the connecting elements indicated as broken away; Figure 3 is a like view on the line 3-3 in the direction of the arrows as shown on Figure 2,y

underlying parts being shown by broken lines; Figure 4 shows the reed-holder and-reed; Figure 5 shows the reed-holder and groove therein; and Figure 6 is a view in horizontal section on the line 6-6 in the direction of the arrows as shown' on Figure 2.

Like numerals refer to like parts in the several gures, in which l is the voice-box proper, having the removable cap 2 thereon and the tubular extension 3 of this cap. 4 is the reed-holder and 5 is a groove therein terminating in an outlet 6 formed in the horizontal disk 7 constituting the top of the holder; 8 is the reed which is aiiixed to the holder by frictional engagement between it and a plate 9 held to the disk 7, as by the screw 10, the plate 9 having a flange 11 between which iiange and the face 12 of the reed-holder the reed is tted and further held by the spring or set of the flange.V 13 is a tubular extension of the box and 14 is an aperture in the box. 15 is a exible tube for insertion in the mouth. 16 is a exible tube for connection to the tube 17 extending from the cupped plate 18, which is adapted to be applied to a tracheotomy opening in the neck. The neck-connection shown is merely illustrative of an operative device, as the physical or anatomic characteristics of each individual, the shape and size of the l tracheotomy opening, the presence or absence of a tracheotomy tube and other similar condiu tions peculiar to the individual, necessarily modsuch prior instruments, with resultant lack of asstruments are of the fixed reed type. The dis- `5 'advantages of that type, among others, are: the

necessity for frequent adjustment of the reed; breakage of reeds; inconstancy of pitch; the considerable pressure and volume of air required for operability; liability to jamming of the reed when loud speaking isattempted; and inability of the user to lower the voice to a subdued tone in conversation. These physical handicaps are productive of uncertainty in the` operation of 15 surance on the part of the users.

Our invention avoids all these obstacles by the use of a beating-reed fixed at one end only, in conjunction with a holder therefor having a curved face, and a groove the depth of which is graduated to decrease from the end at which the reed is flxedvto the end over which the reed is freely suspended, as shown in Figure 2. The reed is broader than, the groove, as shown in Figure 3, and constitutes what is termed a beating-reed. i

By the curvature of the surface of the holder and the use o f a reedKbroader than the groove therein, the reed bends with a rolling motion as it gradually covers the groove until it tends to close it at each vibration, as hereinafter more fully described.

In the embodiment of our invention illustrated, the relative proportionality of the parts is that which has been proven by extended use to afford the best results. The dimensions of these parts are substantially as follows:

The reed, which is preferably of hard-rubber', is between .015 and .016 inch in thickness, but such thickness may range between .012 and .018 without detriment to its desired mechanical and vibratory characteristics. The breadth of the reed at its fixed end is 1% inch, and it tapers to a breadth of 1A inch toward the rounded end which is elliptic, as shown, but these dimensions and conguration are not essential, as the' breadth is determinedy by the width of the groove which it must exceed in order to cover it and leave a margin of the reed overlying the curved face of the holder. While the length of the reed here shown approximates 1.5 inches, the length thereof free to vibrate is determined by the pitch of the voice of the user. Thus shortening the reed, as by cutting oi the upper end, increases the vibration frequency and raises the voice pitch. 65

The length of the reed must be proportioned in accordance with the requirement of each individual. s'

groove .in the holder is preferably 1% inch wide, and its depth is graduated from at the bottom-to V8 at its top. 'The hole in the plate forming the top of the holder in communication `with the groeve tapers to a diameter of .205 inch.

These determinations were found to permit the greatest velocity of air through the slit formed between the reed-tip and the planar face terminating the holder below the groove, while'aording the maximun volume of air for a minimum pressure.

The reed-holder is positioned in the box by means oi the disk forming its to'p, which is peripherally seated upon-the upper edge of the tubular box and held thereto by an interior shoulder in the removable cap which is threaded to screw upon the box, but any suitable mechanical means may be used in mounting the reed-holder in the box without departure from the spirit of our invention. A

The curvature of the face of the holder upon which the reed beats is not uniform. It is preferably iiat at the point of insertion of the reed and substantially so for approximately quarter of an inch from that point. The curvature thereafter is slight for substantially half an inch, and then its degree increases for the next quarter inch, and then further increases to the extremity of the holder, which extends about a quarter inch beyond the end of the groove. With this contour, the flexible reed can bend so as to come down smoothly and dat, and thus progressively shut oif the air passage from the base, or xed end, to the tip, or free end; so that as the closure proceeds, it does so with certainty and uniformity, and the reed gradually covers the opening, with constant and even diminution oi' the air stream. 'Ihe vibratory action of the reed is to bend on the face of the holder like a covering ap until it hasnearly closed it. The beating reed, when adjusted, or voiced, closes with a rolling motion and thus gradually covers the aperture of the groove, whereby the harshness of quality consequent upon a sudden discontinuity is obviated.

. (Glairebrooks Dictionary of Applied Physics.)

The diameter of the interior oi' the cylindrical portion of the box is one-half inch, and its length approximately two and a quarter inches. The upper tubular extension is inch, and the lower is inch. The opening in the side ofthe box is about i. inch.

'Ihe function of the aperture 14 is to permit passage of air through the box to the lungs of the user. It is normally closed by the thumb of the user, the thumb being removed when he needs to inhale or exhale. v

In the form of neck-construction illustrated, the cupped-plate carries a valve, not shown, for purposes of breathing, should the user fail to remove his thumb. This neck-construction is masacre shown merely as a conventional accessory to our invention, which may be attached in any desired 'may be hushed and connected by rubber tube to the collection of moisture between the reed and.

the holderis prevented by the curvature of the contact face of the holder, whereby freezing of the reed to the holder is obviated together with the tendency of a moist reed to cling to the holder and stickl in cold weather,`conditions which made prior devices non-usable at low temperatures; no unusual effort is required on the part of the user to operate our device, due to the size of the groove in the reed-holder and theair-passages provided, whereby a very low pressure gives a maximum volume of air therethrough.

Our invention is susceptible o1' adaptation and application in variously modified forms, as will be apparent to those skilled in the art; and We do not intend to be understood as limiting it to the particular embodiment thereof herein shown and described, save -as may be required by the scope of the appended claims, wherein .the word reed is used to denominate a vibratory element of the frely'suspended type, namely, a ilat beatingreed of thin hard rubber which is neither reenforced, stiffened or weighted, and which is adapt-l Patent is:

An artii'lcial larynx comprising, a cylindrical air-chamber having a cap and a tubular extension from saidcap; a reed-holder comprising a. circular plate and a channelled member' depending therefrom; the said plate being held peripherally against the upper' edge of the air-chamber by said cap; an orifice in said plate communicating with said channel; a beating-reed xed at its upper end to said reed-holder and covering the channelled front thereof; and a tubular extension from the bottom oi' said chamber,'whereby an air passage is ail'orded extending from and through the bottom extension to and through the cap extension and including the reed-covered channel.

CHARLES SHEARD.

ADRIEN N. PORTER. 

